Quran 2:279 — The Heifer (Al-Baqarah)

If you do not, then expect a war from GOD and His messenger. But if you repent, you may keep your capitals, without inflicting injustice, or incurring injustice.

[2:278] O you who believe, you shall observe GOD and refrain from all kinds of usury, if you are believers.

[2:280] If the debtor is unable to pay, wait for a better time. If you give up the loan as a charity, it would be better for you, if you only knew.